The influence of microtexture tools on the geometric morphology of serrated chips based on stress triaxiality.

Purpose: This study aims to investigate the effect of microtextured tools on the geometric morphology of serrated chips, and further improve the cutting performance of polycrystalline cubic boron nitride (PCBN) tool and extend the tool life and the surface quality of the machined surface. Design/methodology/approach: A three-dimensional finite element cutting model of hardened steel AISI D2 with microtextured PCBN tools were established using the finite element software Abaqus, and cutting tests were carried out. Furthermore, the stress distribution in the primary deformation zone was investigated based on the triaxiality of stress, and the influence of microtexture on the geometric morphology of serrated chips and crack development was researched. Findings: The results show that compared with nontexture tools, elliptical pits and wavy grooves microtexture tools have lower serrated degree Gs, higher serrated frequency f per unit length and more miniature serrated step Pc. The serrated phenomenon is intensified because the tensile stress zone of chips generated by nontextured tools is longer than that of elliptic pits and wavy grooves microtexture tools. Simultaneously, the maximum value of triaxiality in the tensile stress zone achieved by nontexture tools is larger than that of the two microtexture tools, and chips obtained by nontextured tools are more susceptible to propagation fractures. Originality/value: This paper mainly studies the effect of microtexture on chip microgeometry, which is relatively little studied at present. At the same time, this paper has a certain engineering significance for PCBN tool turning hardening steel. Peer review: The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-05-2023-0149/ [ABSTRACT FROM AUTHOR]